WLHS / AP BIO / Monson / Unit 4 - Energetics Name
PRELAB for AP LABORATORY: Photosynthesis – Leaf Disk Assay
**Read through the entire laboratory packet and answer the questions below. This will be stamped for completion and reviewed before we do the lab!
BACKGROUND:
1) Define the following terms:
● photosynthesis:
● chloroplast:
● chlorophyll:
2) Write the unbalanced equation for photosynthesis.
(see background info)
3) Write the balanced equation for photosynthesis.
(see notes or CH 10)
4) What are MESOPHYLL cells? How are they organized in leaf tissue? Why?
5) What are STOMATA? What is their purpose?
6) What is the source of the CO2 used by plants in photosynthesis? How does it enter a leaf?
7) What gas is produced in photosynthesis? Why is this significant to us?
8) In this lab, how will we increase the amount of CO2 available to our plant leaves?
PROCEDURE:
1) How will we remove air from the spaces within the leaf tissues?
2) What will happen to the leaf disks as they are allowed to photosynthesize? Why?
3) PREDICT: How will the rate of photosynthesis differ in plain water compared to a solution to which we’ve added NaHCO3? WHY?
**STOP HERE until after you have practiced the procedure & established baseline rates!
DESIGN AN INVESTIGATION:
Once you have mastered the floating disk technique, design an experiment to test another variable that might affect the rate of photosynthesis. Some ideas include, but are not limited to:
● environmental variables – how do you think they would affect photosynthesis rate?
● features or variables of the plant leaves – how do you think they would affect photosynthesis rate?
RECORD YOUR GROUP’S PLAN BELOW:
VARIABLE / QUESTION you will investigate:
SKETCH & LABEL your group’s experimental set-up:
HYPOTHESIS / PREDICTION: What outcome do you predict and WHY?